Automatic water shutoff systems for appliances, such as automatic washing machines, water heaters, and the like are known for cutting off the water supply to an appliance in the event of a malfunction, such as leaking or overflowing, which may cause flooding in the room that the appliance or machine is located. An example of a leak detection system is described in U.S. Pat. No. 3,770,002, issued Nov. 6, 1973, which shows an electrical water sensor having electrical characteristics which vary when the sensor is wetted, and means for actuating the shutoff valve to a closed position in response to the changes in sensor characteristics. The sensor is an electrical structure comprising a base capacitor plate separated by a layer of porous wick-like dielectric material, which functions as capillary means. The arrangement shown and described in the foregoing patent is rather complicated, and depends upon the wetting of the sensor sufficiently to change the leakage resistance of the detector, and thereby the operating state of a relaxation oscillator. It should be apparent that the reliability of such a device is severely in doubt, and that the use of simple operating members, such as in applicant' s construction, greatly increases the reliability and repeatability of the device. U.S. Pat. No. 3,473,553 is another example of a prior art construction directed to an automatic water cutoff for a water heater in which a chamber underneath the heater tank is located for collecting leakage. In addition, the disclosure describes and shows a float that is elevated by water to activate a microswitch, for cutting off the water supply to the water heater.
Neither of the above described patents have the construction and concept of a simplified water safety valve for domestic and industrial use in accordance with present teachings, which has consistent reliability in shutting off the main water or liquid supply when there is either freezing and bursting of the pipes, or leakage in the pipes in either a residence or other type of building.
The present invention relates to a water safety valve, and more particularly to a fast closing valve operated by an electric solenoid which senses even a small amount of water on the floor of the room. It is a feature of the present invention to provide a fast-acting valve mechanism for shutting off the main water supply to a building, upon leakage or bursting of pipes within the structure.
It is another feature of the present invention to have the capability of placing water or liquid sensors in any selected location in a building. In addition, the number of water sensors employed can be varied in accordance with the user's requirements.
The present invention includes the additional feature of a power interrupter for shutting off the power source to the valve assembly, immediately after the main water shutoff valve has been closed.
A further feature of the present invention is the ability to adapt the present invention to new construction wherein the assembly for shutting off the mains water input to the building, as well as an AC power interrupter, can be mounted directly within the walls of the new construction so that the mechanism is hidden from view, leaving only the small water sensors visible in vulnerable areas, such as adjacent to sinks and water tanks. The unit can also be strategically placed near the main water line into the building.
It is another feature of the present invention to provide a liquid or water sensor which, after being contacted by the liquid, acts positively to make an AC circuit whereby the water shutoff mechanism is activated, and a split second later the power source to the AC circuit is cut off.
Another feature of the present invention is a safety valve arrangement for both water and any other type of liquid, such as liquid chemicals. Thus, the automatic safety valve and power interrupter in industrial applications, not only prevents further liquid flooding after detection, but also prevents fires and explosions by opening the electric circuit within the split second after the main liquid shutoff is accomplished.
A further feature of the present invention is the use of the present water safety valve mechanism for marine craft, such as power boats, whereby the shutoff valve would be incorporated in the exhaust pipes of the boat to prevent taking on of water in the boat through said pipes.